Port to Gtk4/Adwaita, taking advantage of Adwaita's recolouring features and thus removing our dependency on sassc. We now require that Vte is be built with gtk4 support. Nautilus Plug-in has been moved upstream. Simon McVittie improved our handeling of custom shells/commands, fixing several bugs and providing a more predictable experience. Colin Kinloch provided fixes for drag-n-drop, with local URIs now being converted to regular fileystem paths. Assorted other fixes were contributed, including detection of man page links, keyboard shortcuts, clipboard oddities, building with clang, and assorted ancillary data updates. Updated Translations: * Abkhazian (Nart Tlisha) * Basque (Asier Sarasua Garmendia) * Catalan (Jordi Mas) * Chinese (China) (Luming Zh) * Dutch (Hannie Dumoleyn) * French (Irénée THIRION) * Galician (Fran Dieguez) * Georgian (Zurab Kargareteli) * German (Jürgen Benvenuti) * Hebrew (Yosef Or Boczko) * Indonesian (Kukuh Syafaat) * Nepali (Pawan Chitrakar) * Persian (Danial Behzadi) * Portuguese (Hugo Carvalho) * Russian (Aleksandr Melman) * Serbian (Марко Костић) * Spanish (Daniel Mustieles) * Turkish (Emin Tufan Çetin) * Ukrainian (Yuri Chornoivan) * Vietnamese (Ngọc Quân Trần)